28 July 2009

Kevin has more on the reports that Jackson may have died from a propofol ... well, I was going to say "overdose" but that's not quite right. Jackson may have died from the predictable effects of using propofol outside of a carefully monitored medical suite:

According to ABCNews, “the autopsy of Michael Jackson found the powerful anesthetic propofol, as well as several prescription drugs, in his system, and law enforcement sources say that investigators believe their final report will list the propofol as a ‘contributing factor’ in his death.”

Wow. Just wow.

For those of you who may not be doctors, this is something just shy of "unbelievable." Propofol is an awesome drug for procedural sedation, but it's got to be used with real respect. It's most typically used as an induction agent for general anesthesia by anesthesiologists in the operating room. At our hospitals we use it for moderate and deep sedation for painful procedures in the ER. We had to go through quite a fight to get it, too. The anesthesia service blocked us for years, contending that this medication is terribly dangerous and that ER docs lack the necessary training to safely use this drug. ER docs -- the ones who intubate and sedate patients every single day of our working life!

Truth be told, they had a point. Not about our skill set, of which they were totally ignorant. But about propofol. It's dangerous if not used carefully. A little too much (or a patient a little too sensitive) and you have a patient who is not breathing any more. If you don't carefully monitor the patient's respirations you may not even notice that they are no longer breathing. Since there is no reversal agent, if you put them too deep you had damned well be ready to manage their airway, or at a bare minimum provide some rescue breaths with a bag-mask device.

So we use it, but only in a selected subset of patients (ASA Class I and II) and in carefully controled environments and with extreme caution.

Part of that caution is due to the fact that people are really unpredictable as to their dosing requirements. A "standard" dose might be 1 mg/kg, or about 70 mg for a typical adult. But some folks are snoring (a sign of possible airway compromise) at 30 mg, and I've seen children use a whole bottle (200 mg or about 8 mg/kg) and still scream and thrash their whole way through the procedure. There's no way to predict reliably, so you give it carefully and slowly and monitor the patient's response.

So the suggestion that some dipshit "cardiologist," who was according to reports not certified by the ACC, thought it was a good idea to give propofol to an unmonitored patient in an out-of-hospital setting for no possible justifiable purpose just blows my mind. Bear in mind that this drug is the one that is so dangerous that anesthesia thinks ER docs are too dumb to use. And he thought that a private home was an appropriate venue for its use.

If it's true, there have got to be consequences for the physician. In the medical world, you tend to think of consequences being malpractice or losing one's job -- not severe enough. Losing his license? Closer, but still not severe enough. He should go to jail for manslaughter. Seriously. If it's true, Dr Murray killed Michael Jackson as surely as if he'd used a gun. And the act of using propofol in a patient's home is reckless beyond any possibility of redemption. It's willful and wanton negligence, and while I know jack squat about California law, there's got to be some sort of law regarding negligent homicide with real penalties.

...and propofol isn't exactly a long-acting drug, which would leave you to believe that this "cardiologist" was running a propofol infusion for hours on-end. On a non-intubated patient. Probably with little-to-no monitoring of vital signs.

I said the same thing when I read that overnight last night. Who the HELL is using propofol at home is batshit crazy enough, but then using it AT HOME without AIRWAY EQUIPMENT or airway TRAINING is super duper batshit insane.

It's dangerous if not used carefully. A little too much (or a patient a little too sensitive) and you have a patient who is not breathing any more. If you don't carefully monitor the patient's respirations you may not even notice that they are no longer breathing. Since there is no reversal agent, if you put them too deep you had damned well be ready to manage their airway, or at a bare minimum provide some rescue breaths with a bag-mask device.

Does that mean that we should be cavalier about other sedatives/anesthetics/opioids?

We should view all of these medications as having the potential to cause respiratory depression/arrest.

The drug is not what is dangerous.

It is the person administering the drug. Anyone who does not understand that these medications operate on a continuum, should not be administering them to patients, regardless of where they are or what license/board certification they possess.

Even a basic drug, like morphine has such a broad range of effective doses in just the opioid naive population, that dosing and not repeatedly reassessing, is not good patient care. It is also not safe, unless patients are routinely receiving inadequate analgesia.

We depend on reversal agents much more than we should. Except in the rarest of cases, the only respiratory stimulus a patient should need for iatrogenic respiratory depression, is just talking with the patient. A patient, who is talking is breathing.

The need for this intervention should not be common, but much less common should be the patient, who actually requires more than just conversation for respiratory depression.

You write, "We should view all of these medications as having the potential to cause respiratory depression/arrest. The drug is not what is dangerous."

And I totally agree. I can say with pride that I've never had to use a reversal agent in a sedation procedure since residency.

The fact that there is no reversal agent for propofol does imbue it with a bit more potential for harm is misused. There's no reversal (except time). And it's easier to induce apnea with it, especially if the patient's had narcs beforehand. So you're right, but propofol does have a higher risk profile.

I'm not intending this as criticism of you, but to remind people not to become overly confident. That is where the problems come from.

I agree that it is more dangerous. My point is that we sometimes act as if there are safe drugs.

In the preapproval studies of propofol 1/8 of patients experienced more than 1 minute of apnea. 1/3 of patients (including the earlier 1/8) experienced more than 30 seconds of apnea.

This is just what was allowed to progress for that long. Someone not anticipating this might not observe the patient as carefully as they should. I think that was demonstrated by Dr. Murray in this case.

Reports of no pulse oximetry and no ECG. Presumably no waveform capnography and no support staff. No mention of any BP cuff, automated or manual.

The reversal agent is a crutch. The only reason to use a reversal agent is to free up staff to attend to other patients, or to reverse procedural sedation. Naloxone and flumazenil are convenient, not necessary.

The bigger problem with propofol is when the apnea is not expected. Contrariwise, when administering a paralytic, apnea is expected 100% of the time.

It isn't the apnea that is the problem. It is the unanticipated apnea. The reason the apnea is unanticipated is that it doesn't happen in most cases. Those giving the drug become overconfident.

Shadowfax

About me: I am an ER physician and administrator living in the Pacific Northwest. I live with my wife and four kids. Various other interests include Shorin-ryu karate, general aviation, Irish music, Apple computers, and progressive politics. My kids do their best to ensure that I have little time to pursue these hobbies.

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